A Unique Case of Unilateral Distal Arm Weakness as a Presentation of Myasthenia Gravis

Abstract

Background: Myasthenia Gravis (MG) is an autoimmune neuromuscular disorder which typically presents with fluctuating ocular, bulbar or proximal limbs weakness. Case Presentation: A 71-year-old woman was admitted to our Neurology department with sudden onset of right distal hand weakness which exacerbated within days and subsequently involved also the proximal limbs and ocular muscles following treatment with high-dose steroids (admitted due to suspicion of myelitis). After a broad neurological work up, she was diagnosed with MG, based on the findings of a typical decremental pattern on Repetitive Nerve Stimulation (RNS) test and the presence of Acetylcholine Receptor Antibodies (AChRAbs). Treatment with 5 cycles of plasma exchange induced a dramatic clinical improvement. Conclusion: This case represents an atypical presentation of MG, simulating Cerebrovascular Accident (CVA) or myelitis and unmasking of signs by treatment with high dose of steroids.